Definitely get a prebuy from a mechanic that knows (and has repaired) 3V Modular Ford Cam Phaser issues. 3V 5.4s are famous for the cam phaser issues, but it happens on 4.6s as well (in my opinion, its more common on 5.4s not because of the engine (vs 4.6s), but because of the use case of 5.4...